1. Technical Field
The present invention relates generally to polymeric layer structures that feature a peelable seal and more specifically to the use of such materials for the manufacture of a peelable overpouch and the like.
2. Background of the Invention
In the medical field, primary containers are used to collect, store, transport, and ultimately deliver therapeutic fluids, nutritional solutions, respiratory therapy agents, dialysis solutions, blood, blood products, plasma derivatives, plasma expanders, blood substitutes, anti-coagulants, blood preservatives, and other therapeutic agents. Oftentimes, these primary containers are placed into secondary containers such as an overpouch to maintain the integrity and volume of the agent contained within the primary container. The primary container can be attached to a tubing set or tubing sets and be accompanied by other containers to form a therapeutic fluid delivery set. The overpouch must have a unique combination of properties. For example, it is desirable that the overpouch be optically transparent in order to inspect visually the contents of the primary container for contaminants to the agent contained therein. At a minimum, the transparency must permit the container's label copy to be legible. The material must also be functional over a wide range of temperatures, including the ability to withstand the autoclaving or sterilization process, which is usually accomplished using steam at temperatures of about 121° C. and at elevated pressures.
The overpouch must also be compatible with the film that constitutes the primary container and with itself. That is, the overpouch cannot become wrinkled, discolored, or adhered to other overpouches or to the primary container, each of which would impair (if not preclude) the ability to inspect visually the primary container without removing the overpouch.
The overpouch must also allow easy access to the inside, primary container by providing an “easy-open” feature such as a tear strip, notch, slit, or the like where no cutting implement is needed.
It is also desirable that the overpouch be free from, or have a low content of, low molecular weight additives such as plasticizers, stabilizers and the like, which could be released into the medications or biological fluids that are contained within the primary container inside the overpouch, thereby potentially causing danger to patients who are using such devices. Hitherto, the industry standard material for fabricating an overpouch has been a high density polyethylene (HDPE), such as Fina 7194, which is sold commercially by AtoFina Oil and Chemical Co.
The present invention is provided to solve these and other problems.